添加布局算法并在新建窗口时应用规则

src/include/xcb.h

@@ -24,6 +24,13 @@ xcb_window_t get_root_window(void);
 bool get_window_visible(xcb_window_t window);
 xcb_window_t get_transient_window_for(xcb_window_t window);
 
+typedef struct window_class_instance_t {
+  char class[128];
+  char instance[128];
+} window_class_instance_t;
+void get_window_class_instance(xcb_window_t window,
+                               window_class_instance_t *class_instance);
+
 typedef struct window_geometry_t {
   int32_t x, y;
   uint32_t width, height, border_width;